Reliable Semiclassical Computations in QCD

We revisit the question of whether or not one can perform reliable semiclassical QCD computations at zero temperature. We study correlation functions with no perturbative contributions, and organize the problem by means of the operator product expansion, establishing a precise criterion for the validity of a semiclassical calculation. For $N_f>N$, a systematic computation is possible; for $N_f<N$, it is not. $N_f=N$ is a borderline case. In our analysis, we see explicitly the exponential suppression of instanton effects at large $N$. As an application, we describe a test of QCD lattice gauge theory computations in the chiral limit.Comment: 16 page

Fire clays and refractory materials

“Nor did the primitive metallurgists who were the first to apply this iron rock to practical use imagine, as they toiled over their unsightly furnaces made of common sun dried clay in which there could not be generated sufficient heat to reduce the iron to a liquid form, and to the top of which the smelter might reach with his hand, that in the future this metal would need to be smelted in furnaces that would reach to the tops of their very temples, and at a temperature that would defy the resistance of the firmest granite. But yet these things are all realized by the metallurgist of today and in his construction of the furnaces and various metallurgical apparatuses which are the outgrowth of the various discoveries of metals, and the constant invention of new methods of metallurgical treatment, there is no problem that more keenly taxes his ability than the discovery and application of the most efficient refractory materials which shall be able to endure all the varied requirements of modern metallurgy. Indeed if we examine this subject but a moment we see that it cannot well be otherwise, for what with the immense increase of temperature incident to the introduction of many new processes (of which the Bessemer process for the production of steel may be cited as a single example) and with the unfitness of natural substances, and even the entire range of artificial materials to a certain degree, for the withstanding of such heat, we see nothing but continual embarassment meeting the furnace builder and retort maker whichever way he may turn. Indeed the problem has attained such a degree of complexity through the increasing demands upon our refractory material that certain branches of industry are threatened with extinction.”—Pages 3-5

Hands-On Universe: A Global Program for Education and Public Outreach in Astronomy

Hands-On Universe (HOU) is an educational program that enables students to investigate the Universe while applying tools and concepts from science, math, and technology. Using the Internet, HOU participants around the world request observations from an automated telescope, download images from a large image archive, and analyze them with the aid of user-friendly image processing software. This program is developing now in many countries, including the USA, France, Germany, Sweden, Japan, Australia, and others. A network of telescopes has been established among these countries, many of them remotely operated, as shown in the accompanying demo. Using this feature, students in the classroom are able to make night observations during the day, using a telescope placed in another country. An archive of images taken on large telescopes is also accessible, as well as resources for teachers. Students are also dealing with real research projects, e.g. the search for asteroids, which resulted in the discovery of a Kuiper Belt object by high-school students. Not only Hands-On Universe gives the general public an access to professional astronomy, but it is also a more general tool to demonstrate the use of a complex automated system, the techniques of data processing and automation. Last but not least, through the use of telescopes located in many countries over the globe, a form of powerful and genuine cooperation between teachers and children from various countries is promoted, with a clear educational goal.Comment: 4 pages, 1 figure, to appear in the proceedings of the ADASS X conference, Boston, October 2000, ASP conf. pro

Project for the treatment of an iron ore

So great is the degree of perfection that marks the various processes of iron production that it seems almost useless to essay to further study a subject which has received the best thoughts and lifetime labors of the greatest metallurgists of all ages. Yet as we believe that there are still isolated cases whose various conditions have not received that consideration necessary to the most economical production of the pug; and believing that a most perfect knowledge of these conditions is essential to the final perfection of the metallurgy; and knowing further that a wide extended interchange of experience and discoveries alone can perfect any science we have undertaken the study of an individual case --page 2

Silver amalgamation

The process of amalgamation is one of the oldest known methods of extracting silver from its ores. The process arose from the finding of rich silver ores in districts where little or no fuel existed. This method of silver extraction has been known and used for over three hundred years; but the method of pan amalgamation which came into use much later and has been so fully developed under American management is the one which we will here consider. The process of pan amalgamation is peculiarly adapted to certain mining districts of the western territory of the United States --page 2

Understanding across the senses: cross-modal studies of cognition in cetaceans

Cross-modal approaches to the study of sensory perception, social recognition, cognition, and mental representation have proved fruitful in humans as well as in a variety of other species including toothed whales in revealing equivalencies that suggest that different sensory stimuli associated with objects or individuals may effectively evoke mental representations that are, respectively, object based or individual based. Building on established findings of structural equivalence in the form of spontaneous recognition of complex shapes across the modalities of echolocation and vision and behavior favoring identity echoic–visual cross-modal relationships over associative echoic–visual cross-modal relationships, examinations of transitive inference equivalencies from initially learned associations of visual and acoustic stimuli, and recent work exam- ining spontaneous cross-modal social recognition of individual identity across acoustic and gustatory chemical modalities (i.e., the equivalence relationships among an individual’s characteristics), we examine the history, utility and implications for cross-modal research in cetacean cognition. Drawing from research findings on bottlenose dolphins and beluga whales as well as other species we suggest future directions for cetacean cross-modal research to further illuminate understanding how structural and individual sensory equivalencies lead to object-centered and individual-centered mental representations, as well as to explore the potential for practical applications related to cetacean conservation

Characteristics of a New Carbonaceous Chondrite, Metal-Rich-Lithology Found in the Carbonaceous Chondrite Breccia Aguas Zarcas

The Aguas Zarcas meteorite fell in Costa Rica on 23 April 2019 at 21:07 local time, with a total mass of about 27 kg. Hundreds of fusion-crusted stones ranging from 0.1 to 1868 g were recovered (The Meteoritical Bulletin). The meteorite was classified as a CM chondrite, but some lithlogies show a different texture to that of CM. In this study, we investigated the petrography, mineral-ogy, chemistry, and isotopic composition of an unusual Metal-rich-lithology from this fresh fall